Fish Tissue Targets for PCB TMDLs: What is the Real Risk? An Example from the Greater Los Angeles and Long Beach Harbor Waters TMDL

Total maximum daily loads (TMDLs) are established to attain and maintain applicable Water Quality Standards (WQS) for impaired water bodies. Numeric polychlorinated biphenyl (PCB) criterion in a TMDL for an impaired water body due to fish tissue advisories may be a sediment, water column, or fish tissue-based target. TMDLs should provide documentation of the approach used to establish a linkage between numeric PCB targets and PCB sources (USEPA 2011a). The Final Dominguez Channel and Greater Los Angeles and Long Beach Harbor Waters Toxic Pollutants Total Maximum Daily Load (USEPA 2011b) acknowledges that the relationship between sediment concentrations and fish tissue burden is not well understood in the harbor waters. Therefore, the Ports of Long Beach and Los Angeles are leading multiple efforts in developing special studies and predictive tools to identify the linkages prior to the TMDL reopener in 2016.